A single-surgeon, Level I randomized trial comparing two cruciate-sacrificing TKA inserts: a post-cam posterior-stabilized (PS) design versus a more congruent anterior-lipped condylar-stabilized (CS) design. All PCLs were sacrificed and all knees used the Triathlon system. The question: does the post-cam mechanism actually improve mid-term clinical and radiographic outcomes?
The core decision this paper informs: in a PCL-sacrificing TKA, do you need a post-cam mechanism, or is a highly congruent condylar-stabilized insert enough? At 5 years this single-surgeon RCT found no clinical or radiographic difference between the two, with the CS group reporting fewer mechanical sensations (9% vs 21%).
Understand the mechanism for boards: the PS post engages the femoral cam near 60 degrees of flexion to substitute for the PCL, while the CS design relies on a deeper, more congruent anterior lip for constraint. The post-cam box is also the anatomic source of patellar clunk and clicking.
Weight the evidence carefully. This is a single surgeon using an anatomic, measured-resection technique with minimal ligament releases, and the mechanical-sensation questionnaire was not validated.
The AP stability question remains debated: Sur et al found on stress radiographs that CS inserts do not restore AP stability as well as PS after PCL sacrifice, suggesting the equivalence here may partly reflect insensitive outcome measures.
A single-surgeon, Level I randomized trial comparing two cruciate-sacrificing TKA inserts: a post-cam posterior-stabilized (PS) design versus a more congruent anterior-lipped condylar-stabilized (CS) design. All PCLs were sacrificed and all knees used the Triathlon system. The question: does the post-cam mechanism actually improve mid-term clinical and radiographic outcomes?
The core decision this paper informs: in a PCL-sacrificing TKA, do you need a post-cam mechanism, or is a highly congruent condylar-stabilized insert enough? At 5 years this single-surgeon RCT found no clinical or radiographic difference between the two, with the CS group reporting fewer mechanical sensations (9% vs 21%).
Understand the mechanism for boards: the PS post engages the femoral cam near 60 degrees of flexion to substitute for the PCL, while the CS design relies on a deeper, more congruent anterior lip for constraint. The post-cam box is also the anatomic source of patellar clunk and clicking.
Weight the evidence carefully. This is a single surgeon using an anatomic, measured-resection technique with minimal ligament releases, and the mechanical-sensation questionnaire was not validated.
The AP stability question remains debated: Sur et al found on stress radiographs that CS inserts do not restore AP stability as well as PS after PCL sacrifice, suggesting the equivalence here may partly reflect insensitive outcome measures.